Some teachers from Cook County school district in Illinois requested some enhancements for my site. The test version debuts on this lesson:

Quadratic Equation

The old quadratic lesson showed you the answer and math work. The new quadratic lesson shows you how to plug back in the answers you got to prove the answer you got was correct, as well as a random quadratic problem generating button that generates random quadratic problems.

Let me know if you find errors or want enhancements.